Additive manufacturing enables creation of complex structures along with spatially-varying properties. In additive manufacturing, each process along the way from powder to part must be optimized to ensure ultimate success. For example, besides the size and shape of the powder particles, the micro-structure of the powder particles can also influence the manufacturing process. Tailoring the powder micro-structure via, e.g. annealing, can change how that powder interacts with the specific conditions of a manufacturing process. In this study we present a correlative workflow with nanoCT and FIB-SEM+EDS techniques to show the effect of heat treatment in Aluminum 6061 powder particles. Using X-ray nanoCT, we imaged the internal microstructure of a single (~40 µm) powder particle at resolutions at 50 nm in pristine state and then after annealing. Tomographic analysis reveals several details in the annealed particle that were not present in the pristine particle. The study will present the observed changes during the annealing process. Inspection of the tomograms shows an increase in the size of secondary phases present along grain boundaries. Surface roughness has also increased in the annealed particle, and internal porosity has evolved. Correlative analysis of the internal structures using FIB-SEM + EDS verify the chemical nature of the developing inclusions and shows finer detail of the micro-structure. We will discuss the implications of this analysis towards powder performance in a cold-spray manufacturing process as well as powder recycling using.
- Appreciate the effect of effect of heat treatment on powder micro-structure
- Learn about the application of correlative imaging